Technical information

NewBIOS Reference Serial Solutions
Other Points.____________
IBM documentation does not mention the 5- and 6-bit
word length settings on the 16450, but these are faithfully
written to the 16450 by this service, in both its IBM and Serial
Solutions form, as above.
IBM documentation treats the return values of services 0H
to 5H as the same, listing values which are an amalgam of the
correct ones for various services. This listing is more faithful to
the IBM routines and the Serial Solutions routines.
Chapter 5 Page 77